Concrete insert



Dec. 8, 1970 F. K. KNOHL CONCRETE INSERT Filed July 5, 1968 INVENTOR.Fr/ear/ch Karl Knoh/ His Arr s CONCRETE INSERT Friedrich Karl Knohl,Roselle, I]l., assignor to Illinois Tool Works Inc., Chicago, 111., acorporation of Dela- Ware Filed July 3, 1968, Ser. No. 742,437 Int. Cl.E04b 2/20, 2/48 U.S. Cl. 52367 11 Claims ABSTRACT OF THE DISCLOSURE Inassembling wood, metal and concrete sections to a concrete support, ithas been the practice to drill holes in the concrete support into whichare placed fastener devices which anchor themselves to the concretesupport and at the same time provide attachment or fastening means whichsecures the wood, metal or concrete section to the concrete support. Itwill be readily apparent that drilling holes in a concrete support istime consuming, and further, fastener devices for mounting in such holeshave been difficult to assemble to the concrete support as Well as tothe section which is assembled thereto. As a result, various types ofconcrete inserts have been developed which can be placed within theconcrete support prior to its hardening so as to be captured therebywhile permitting access thereto for attaching various types of wood,metal and concrete sections to the concrete support. While concreteinserts have provided eflective individual attachment means, theygenerally require special mounting techniques prior to the pouring ofthe concrete to properly expose the insert for the subsequent fasteningthat is required. The time and expense inherent in such special mountingtechniques has limited broader and consistent uses of concrete insertsin the construction industry. Further, the special mounting techniquesfor concrete inserts have imposed additional limitations on thefastening techniques to be employed as well as the versatility of theconcrete insert to the many possible uses that may be required.

Accordingly, it an object of the present invention to provide an insertfor pre-cast concrete or the like which overcomes the above-mentioneddeficiencies.

More particularly, it is an object of the present invention to providean insert for pre-cast concrete or the like which is capable ofself-positionment and exposure of a surface thereof relative to one faceof the pre-cast concrete to facilitate attachment of a fastening elementthereto, and at the same time provide a concrete void immediately behindthe exposed surface which offers substantially no resistance to afastening element assembled to the concrete insert.

Another object of the present invention is the provision of an insertfor pre-cast concrete or the like which alfords wide flexibility in bothsite alignment as well as the assembly of sections made from differenttypes of material to the pre-cast concrete at a variety of locations.

Other objects of the present invention include the provision of insertfor pre-cast concrete or the like which is of light weight and simpleconstruction, capable of being manufactured and then assembled to aconcrete support by fast, efficient and economical techniques, affordsdurability in use over long periods, and is otherwise well adapted forthe purposes intended.

United States Patent ice The above and other objects of the presentinvention are attained by the provision of an insert for pre-castconcrete or the like which includes a top wall and side wall dependingtherefrom on opposite sides thereof to define a channel-shaped member,and a floating element mug within the channel-shaped member to positionat least outer marginal surfaces of the top wall thereof substantiallyflush with the top surface of the concrete adjacent the insert prior tothe setting of the concrete, the floating element also being capable ofproviding a concrete void immediately behind the top wall of thechannel-shaped member and having substantially no resistance to afastening element driven therein during attachment thereof to the topwall of the channel-shaped member. The floating element, which may alsobe characterized as the secondary element of the concrete insert, mayalso be capable of being received and retained by the channel-shapedmember.

Reference is now made to the drawings wherein:

FIG. 1 is a perspective view of the preferred form of concrete insertwhich is constructed in accordance with the teachings of the presentinvention;

FIG. 2 is a fragmentary perspective view illustrating the manner inwhich concrete inserts, either in block or in stripform, of the typedepicted in FIG. 1 are capable of being mounted into a pre-cast concretesupport or the like;

FIG. 3 is an enlarged fragmentary end elevational view as viewed alongline 33 in FIG. 2;

FIG. 4 is an end elevational view showing the manner in which afastening element is mounted relative to the concrete insert and holds apre-cast concrete panel relative to the pre-cast concrete support inwhich the concrete insert is mounted; and

FIG. 5 is an end elevational view showing a modified form of concreteinsert which is used in conjunction with a corrugated metal panel andconcrete support assembly.

Reference is first made to FIGS. 1-3 for a description of the preferredembodiment of the present invention. As best seen in these figures, theconcrete insert 10 includes a primary metal channel-shaped member 12into which is mounted a secondary element 14 which is designed toprovide floatation of the concrete insert 10 prior to setting of theconcrete into which it is positioned and at the same time provide aconcrete void immediately behind the top wall 16 of the channel-shapedmember for reasons which will appear hereinafter. Although the secondaryelement 14 can be configured or made from any material which willprovide floatation and concrete void features just mentioned, it hasbeen found that foamed polystyrene block material which is illustratedin FIGS. 1-4 of the drawings or gypsum are preferred constructions. Thefoamed polystyrene blocks 14 are formed in a generally rectangularcross-sectional shape and mounted within the channel-shaped member 12 asillustrated in the drawings.

The metal channel-shaped member may be made from sheet steel such asAISI 1010 in suitable thicknesses as desired. The channel-shaped member12 is formed by suitable dies as a one-piece construction and includes atop wall 16 with side walls 18 depending therefrom on opposite sidesthereof, each side wall 18 terminating in a foot portion 20 at the freeextremity thereof which may be aligned, if desired, with the lower faceof the foamed polystyrene block 14. Each of the side walls 18 flare ortaper downwardly and outwardly from adjacent the juncture with the topwall 16 to facilitate introduction of the foamed polystyrene block 14within the channelshaped member. It will be noted that each of the sidewalls 18 immediately adjacent the juncture with the top wall 16 firstare directed downwardly for a short distance, then proceed downwardlyand outwardly as illustrated. This permits the foamed polystyrene blockto completely underlie the top wall 16 if it is configured to fill upthe space as illustrated in the drawings so that there will be noconcrete immediately below the top wall 16 of the channel-shaped member.

The downward and outward tapering or flare of the majority of the sidewalls 18, together with the laterally outwardly directed foot portion 20associated with each side wall 18, provides a construction which can besecurely retained in a concrete support 22 as best seen in FIGS. 2-3upon hardening thereof.

Preferably, the channel-shaped member includes means for holding thefoamed polystyrene block 14 therewithin. As shown in the drawing, suchmeans may comprise an integral tab 24 struck from each of the side walls18 and extending upwardly and inwardly relative thereto for engaging andretaining the foamed polystyrene block 14 within the channel-shapedmember as best seen in FIG. 3 of the drawing. It is to be noted thateach of the tab means is integrally hinged relative to a respective sidewall along a line generally coincident with the juncture of the sidewall 18 and associated foot portion 20. Thus, each of the tabs 24 areflexibly and hingedly mounted so as to provide the desired flexibilityupon mounting of the foamed polystyrene block 14 within thechannel-shaped member, but upon the complete interfitting movement ofsuch components, the tabs 24 on each of the side walls 18 function asstruck elements to prevent removal of the foamed polystyrene block 14.In this way, the foamed polystyrene block 14 is captured by thechannel-shaped member 12 so that there will be no disassembly during useof the concrete insert.

The apertures 26 in each of the side walls 18 which are formed by theintegral tabs 24 being struck from the side walls 18 enhances theretention of the concrete insert Within a concrete support 22. It willbe readily understood that the concrete can easily flow through theapertures 26 so as to be positioned on opposite sides of each side wall18, foot portion 20 and tab 24 as best seen in FIG. 3 to effectivelyretain the insert within the concrete support.

Since the channel-shaped member 12 and its associated foamed polystyreneblock 14 are light weight in construction, the concrete insert willfloat during the concrete pour such that the top wall 16 of thechannel-shaped member 12 can be positioned flush with the top surface orouter face of the concrete support 22. This is important in providing alarge surface area over which a fastening device, such as theself-drilling and tapping screw 28 shown in FIG. 4, can be attached tothe top wall of the channel-shaped member 12. For a specific descriptionof one type of self-drilling and tapping screw, reference is made to US.Pat. 3,125,923. Where such a fastening element is used for attachment tothe top wall of the channelshaped member 12, it is also important thatthere be a concrete void immediately behind the top wall 16 which offerssubstantially no resistance to a fastening element driven therein duringattachment to the top wall 16.

Thus, in assembling a concrete section 30 to a concrete support 22having a concrete insert 10 as shown in FIG. 4 of the drawings, afastener device such as the selfdrilling and tapping screw 28 must becapable of penetrating the top wall 16 and attach itself relativethereto by tapping threads in the aperture which is formed by theself-drilling fastener 28 without encountering any substantialresistance beneath the top wall 16 of the channelshaped member 12 whichcould substantially hinder and reduce the desirability of using theconcrete insert 10. All of the above features are obtained with the useof the concrete insert of the present invention. It will be noted thatthe concrete section 30 has a tapered hole 32 which aids in aligning theself-drilling and tapping fastener 28 or other equivalent fastenerdevice during attachment to the concrete insert.

The concrete insert 10 of the present invention can be formed into shortsections as shown at the left hand side of FIG. 2 or, alternatively, maybe formed into elongated metal strips which are shown at the right handside of 4 FIG. 2. The concrete insert can be formed in a variety ofconfigurations, including closed figures, if such is desired.

Although the foamed polystyrene block 14 functions well in achieving thedesired purposes, there are other ways of achieving the desired end. Oneexample is shown in FIG. 5 of the drawings wherein the foamedpolystyrene block or secondary element 14 is replaced by a complementarychannel-shaped element 34 which is inverted with respect to thechannel-shaped member 12, but is positioned within and retained by thechannel-shaped member 12 in substantially the same manner as the foamedpolystyrene block 14 in the FIGS. 14 embodiment. The invertedchannel-shaped element 34, as will be seen in FIG. 5 of the drawings,clearly provides a concrete void immediately behind the top wall 16 ofthe channel-shaped member 12 which offers no resistance to a fasteningelement such as the self-drilling and tapping screw 32.

FIG. 5 also illustrates the use of the concrete insert 10 attachingcorrugated metal strips 34 to the concrete support 22 by way of theself-drilling and tapping fastener 32 as illustrated. Thus, the concreteinsert 10 provides the capability of attaching sections of differentmaterial and configurations to a concrete support as will be readilyapparent.

While a self-drilling and tapping fastener 32 may be used in conjunctionwith the concrete insert 10, it is also possible that various types offastening devices may be captured within or attached to the top wall 16of the channel-shaped member to permit attachment of various types ofsections to the concrete support in which the concrete insert 10 ispositioned. Other types of fastening components or extensions, eitherintegral with or attached to the top wall 16 of the channel-shapedmember 12 may be used as desired.

From the foregoing, it will be appreciated that the concrete insert ofthe present invention affords wide flexibility in attaching varioustypes of sections to a concrete support over a wide range of locations,without sacrificing economy, simplicity in construction or ease ofintended use of the device. While the preferred embodiments of thisinvention have been shown and described herein, it is obvious that manystructural details may be changed Without departing from the spirit andscope of the appended claims.

I claim:

1. A fastening insert for concrete comprising a channel-shaped sectionincluding an end wall integrally connected to generally opposed sidewalls, said side walls including generally opposed portionssubstantially normally directed relative to said end wall portion andportions generally flaring outwardly from said substantially normallydirected portions, said flaring portions facilitating introduction of asecondary element within said channel-shaped member, said secondaryelement being a body of material cooperatively mounted within said sideWalls and capable of creating a concrete void immediately behind the endwall thereof to enable a complementary fastening element to be driventherein without offering any substantial resistance to saidcomplementary fastening element during attachment thereof to the endWall of said channel-shaped member, means formed in at least one of saidside Walls to retain said complementary element within thechannel-shaped member, said side walls being laterally spaced from saidsecondary element for at least a part of the axial height thereof, andoutwardly directed foot portions at the terminating extremities of saidflaring portion, said aforesaid means for retaining said secondaryelement within said channelshaped member being a tab extending from thevicinity of the juncture of said outwardly directed foot portions andsaid side wall portions laterally spaced from said secondary element andextending inwardly a distance to permit same to engage said secondaryelement to assure positive retention of said element within saidfastening insert whereby the arrangement of said opposed side walls,laterally spaced side wall portions, associated foot portions andretaining means all facilitate the secure retention of the insert Withinthe concrete when said complementary fastening element is attached tothe end wall of said channel-shaped member.

2. A fastening insert for concrete comprising a channel-shaped sectionincluding an end wall integrally connected to generally opposed sidewalls, said side walls including generally opposed portionssubstantially normally directed relative to said end wall portion andportions generally flaring outwardly from said substantially normallydirected portions, said flaring portions facilitating introduction of asecondary element within said channel-shaped member, said secondaryelement being a body of material cooperatively mounted within said sidewalls and capable of creating a concrete void immediately behind the endwall thereof to enable a complementary fastening element to be driventherein without offering any substantial resistance to saidcomplementary fastening element during attachment thereof to the endWall of said channel-shaped member, means formed in at least one of saidside walls to retain said secondary element within the channel-shapedmember, said side Walls being laterally spaced from said secondaryelement for at least a part of the axial height thereof, and outwardlydirected foot portions at the terminating extremities of said flaringportion whereby said foot portions and the generally opposed side wallportions cooperate to securely retain the insert imbedded in theconcrete when said fastening element is attached to the end wall of saidchannel-shaped member.

3. The insert as defined in claim 2 wherein the generally verticallydirected portion of said side walls is located immediately adjacent theend wall thereof.

4. The insert as defined in claim 2 wherein the interconnecting portionat the juncture of said generally vertically directed portion and theend Wall is generally rounded.

5. The insert as defined in claim 2 wherein said secondary element iscapable of causing the insert to float in unset concrete.

6. The insert as defined in claim 2 wherein said secondary elementcomprises a complementary channelshaped element which is inverted withrespect to said first mentioned channel-shaped member.

7. The insert as defined in claim 2 wherein said secondary elementcomprises a one-piece, plastic material block.

8. The insert as defined in claim 2 wherein said onepiece, plasticmaterial block consists of a lightweight, closed-cell structure.

9. The insert as defined in claim 2 wherein said onepiece, plasticmaterial block is formed polystyrene.

10. The insert as defined in claim 2 wherein said generally opposedmeans comprises a pair of opposed tab means which extend inwardly andare inclined relative to the side wall with which such tab means isassociated.

11. In combination, the fastening insert as defined in claim 2, saidfastening insert being secured to a pre-cast concrete support, a sectionto be attached to the concrete support, and a headed fastening devicewhich attaches the section to the concrete support, said section havinga tapered hole extending therethrough which is configured and arrangedrelative to the head of the fastening device to prevent tilting thereofduring attachment of the fastening device to the fastening insert.

References Cited UNITED STATES PATENTS 1,668,842 5/1928 Dudfield et al.52374 2,410,299 10/ 1946 Murtagh 52374 3,181,486 5/1965 King 525993,221,588 12/1965 Wieber 52363 3,401,494 9/1968 Anderson 52363 3,420,0321/1969 Felt 5273 1 FOREIGN PATENTS 838,452 6/ 1960 Great Britain 52373960,909 11/1949 France 52367 FRANK L. ABBOTT, Primary Examiner I. L.RIDGILL, 111., Assistant Examiner US. 01. xi 52-372, 576, 73a

